Carbamic pesticidal compositions

ABSTRACT

N-haloalkanesulfenylcarbamoyloxime compositions have been found to have exceptional miticidal and insecticidal activity.

This application is a division of my copending U.S. application Ser. No.483,882, filed June 27, 1974, now U.S. Pat. No. 4,029,688.

This invention relates to novel compositions of matter and to their usein combating insects and mites.

The compounds which are employed as the active ingredients in thepesticidal compositions of this invention are new compoundscorresponding to the following general formula: ##STR1## wherein:

R is:

A. lower alkyl;

B. lower alkyl substituted with one or more lower alkoxy, loweralkylthio, lower alkylsulfinyl, lower alkylsulfonyl, phenylthio,phenylsulfinyl, phenylsulfonyl or R₄ CON(R₅)--, all of which may besubstituted with one or more cyano, nitro, azido, chloro, bromo orfluoro substituents;

R₁ is:

A. hydrogen, chlorine, bromine, fluorine, cyano;

B. alkyl having from 1 to 4 carbon atoms, lower alkylthio, lower alkoxy,lower carboalkoxyalkylthio, lower alkylthioalkyl, all of which mayeither unsubstituted or substituted with one or more chloro, bromo,fluoro cyano or nitro groups.

R₂ is lower alkyl or lower alkyl substituted with one or more chloro,bromo, fluoro, nitro cyano, lower alkoxy or lower alkyl groups;

R₃ is perhalomethanesulfenyl or perhaloethanesulfenyl wherein thepermissible halogen substituents are chloro, bromo or fluoro;

R₄ and R₅ are individually hydrogen or lower alkyl; with the provisothat

A. when R is alkyl, R₁ is substituted lower alkyl, substituted loweralkylthio, unsubstituted or substituted lower alkoxy, unsubstituted orsubstituted lower carboalkoxyalkylthio or unsubstituted or substitutedlower alkylthioalkyl;

B. when R₁ is hydrogen, R is other than unsubstituted loweralkylthioalkyl; and

C. at least one of the groups R, R₁ and R₂ is a group including one ormore cyano substituents when R₁ is other than cyano.

Compositions including these compounds as the active ingredient, areuseful in combating insects and mites. In general, the compositionshaving the greatest degree of pesticidal activity are those in which thecombined total number of aliphatic carbon atoms in the ennumeratedsubstituents does not exceed about 10 carbon atoms.

The preferred compositions of this invention are those in which R₂ ismethyl and R₃ perhalomethanesulfenyl.

It will be appreciated that the active compounds of this invention willexist in at least two isomeric forms. In the "syn" configuration, theoxygen atoms of the oximino function is on the same side of the oximinodouble bond as the R substituent in the generic formula set forth abovewhile in the "anti" configuration, the pg,6 oxygen atom is on theopposite side of the oximino function. Both isomers are within the scopeof our invention, however the syn isomers are preferred due to theirgreater biological activity.

The novel compounds of this invention in comparison to the correspondingN-methylcarbamate compounds, some of which are well known insecticides,have been found to possess essentially equivalent insecticidal andmiticidal activity although in some cases enhanced activity againstparticular pests have been observed. Surprisingly, however, thecompounds of this invention demonstrate a sharp reduction in mammaliantoxicity as compared to the N-methyl compounds. In addition nearly allof the novel compositions of this invention are quite stable undernormal conditions and can be stored for long periods of time withoutappreciable loss or reduction in biological activity. This is to becontrasted with many of the corresponding N-methyl carbamatecompositions which are relatively unstable and can not be stored for anyappreciable length of time and as such are not useful pesticides becauseof practical considerations.

Compositions which exhibit the greatest stability, and generallyenhanced pesticidal activity are those in which the cumulative sigma*value of the groups R and R₁ of the active compound is at least 1.1.

This problem of instability is particularly acute in the case ofcompounds of the type described above wherein R₁ is hydrogen if there isnot present a relatively strong electron withdrawing function in the Rsubstituent. Certain compounds, such as those in which R₁ is hydrogenand R is alkylthio are unstable despite the relatively strong electronwithdrawing character of the alkylthio substituent. These compounds arenot included within the scope of the generic formula as defined above.

The active compounds of this invention can be prepared conveniently inaccordance with the following general reaction scheme: ##STR2## where R,R₁, R₂ and R₃ are as described above and where X is either chlorine orfluorine.

The oxime precursors used in the preparation of the active compounds ofthis invention can be prepared by conventional means as for example bythe methods described in U.S. Pat. Nos. 3,217,036, 3,217,037, 3,400,153,3,536,760 and 3,576,834.

The carbamic acid fluoride precursor compounds can be prepared by themethod described in U.S. Pat. No. 3,769,471. The carbamic acid chloridecompounds can be prepared by the method described in Belgium Pat. No.796,646.

The reaction between the oxime compound and the carbamic acid halidcompound is preferably carried out in an aprotic solvent and in thepresence of a base. The preferred base materials are tertiary amines andalkaline earth bases. Yields obtained by this reaction are generallyquantitative.

The following specific examples are presented to more particularlyillustrate the manner in which the active compounds of this inventionmay be prepared.

EXAMPLE I

To a solution of 2.26 g (0.0111 m)N-methyl-N-trichloromethanesulfenylcarbamyl fluoride and 1.29 (0.011 m)2-methyl-2-cyanopropionaldehydeoxime in 75 ml dioxane was added dropwisewith stirring 1.28 g (0.013 m) triethylamine. The spontaneous exothermraised the temperature from 23° to 29° C. After stirring for anadditional period of 0.5 hr at ambient temperature, the reaction mixturewas quenched with 300 ml of water. The product was extracted intoethylene acetate and the resulting solution was dried over magnesiumsulfate and concentrated to a residual oil which crystallized fromisopropyl ether to yield 2.0 g of the desired product2-methyl-2-cyanopropionaldehyde-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oximemp 105°-107° C. Recrystallization raised the mp to 111°-113° C.

Analysis - Calcd. for C₈ H₁₀ N₃ O₂ Cl₃ S: C, 30.16; H, 3.16; N, 13.19Found: C, 30.15; H, 3.29; N, 13.36

EXAMPLE II

To a solution of 1.1 g (0.008 m) 1-(2-cyanoethylthio)acetaldoxime, and1.8 g (0.008 m) N-methyl-N-(trichloromethanesulfenylcarbamoyl) fluoridein 50 ml of dioxane was added dropwise with stirring at 28°-30° C, 0.9 gof triethylamine. After stirring overnight at ambient temperature, thereaction mixture was poured in 500 ml of water and stirred for 10minutes. The precipitated solid was washed with water and dried. Onrecrystallization from isopropanol it yielded 1.1 g of1-(2-cyanoethylthio)acetaldehyde-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime,mp 136°-138° C.

The following compositions in addition to those described in the aboveexamples are illustrative of the new compositions of this invention:

2-Phenylthio-1-cyanoacetaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

1-(2-Cyanopropylthio)acetaldehyde O-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

1-(2-Cyanomethylthio)acetaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Cyano-2-methyl-1-(2-cyanoethylthio)propionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Nitro-2-methyl-1-(2-cyanoethylthio)propionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-cyanopropionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

3-Methyl-3-cyanobutanone-2O-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.3-Cyanobutanone-2 O-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-cyanopropionaldehyde O-(N-methyl-N-trifluoromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-cyanopropionaldehydeO-(N-methyl-N-fluorodichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-(cyanoethyl)thiopropionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-methoxy-1-cyanopropionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-methylthio-1-cyanopropionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Cyano-2-methyl-1-methylthiopropionaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

1-(2-Cyanoethylthio)acetaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.

1-(2-cyanoethylthio)acetaldehydeO-(N-methyl-N-trifluoromethanesulfenylcarbamoyl)oxime.

1-(2-cyanoethylthio)acetaldehydeO-(N-methyl-N-fluorodichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-cyanopropionaldehydeO-[N-(2-chloroethyl)-N-trichloromethanesulfenylcarbamoyl]oxime.

2-Methyl-2-cyanopropionaldehydeO-[N-(n-propyl)-N-dichlorofluoromethanesulfenylcarbamoyl]oxime.

2-Methyl-2-cyanopropionaldehydeO-[N-(2-nitroethyl)-N-trichloromethanesulfenylcarbamoyl]oxime

2-Methyl-2-cyanopropionaldehydeO-(N-cyanomethyl-N-trichloromethanesulfenylcarbamoyl)oxime.

2-Methyl-2-cyanopropionaldehydeO-(N-vinyl-N-trichloromethanesulfenylcarbamoyl)oxime

2-Methyl-2-cyanopropionaldehydeO-(N-benzyl-N-trichloromethanesulfenylcarbamoyl)oxime

2-Methyl-2-cyanopropionaldehydeO-(N-phenyl-N-trichloromethanesulfenylcarbamoyl)oxime

2-Methyl-2-cyanopropionaldehydeO-[N-(4-chlorophenyl)-N-trichloromethanesulfenylcarbamoyl]

2-Methyl-2-cyanopropionaldehydeO-[N-(4-methoxyphenyl)-N-trichloromethanesuflenylcarbamoyl]oxime

Selected species of the new compounds were evaluated to determine theirpesticidal activity against mites, nematodes and certain insects,including an aphid, a caterpillar, a beetle and a fly.

Suspensions of the test compounds were prepared by dissolving one gramof compound in 50 milliliters of acetone in which had been dissolved 0.1gram (10 percent of the weight of compound) of an alkylphenoxypolyethoxyethanol surfactant, as an emulsifying or dispersing agent. Theresulting solution was mixed into 150 milliliters of water to giveroughly 200 milliliters of a suspension containing the compound infinely divided form. The thus-prepared stock suspension contained 0.5percent by weight of compound. The test concentrations in parts permillion by weight employed in the tests described hereinbelow wereobtained by appropriate dilutions of the stock suspension with water.The test procedures were as follows:

Bean Aphid Foliage Spray Test

Adults and nymphal stages of the bean aphid (Aphis fabae Scop.) rearedon potted dwarf nasturtium plants at 65°-70° F. and 50-70 percentrelative humidity, constituted the test insects. For testing purposes,the number of aphids per pot was standardized to 100-150 by trimmingplants containing excess aphids.

The test compounds were formulated by diluting the stock suspension withwater to give a suspension containing 500 parts of test compound permillion parts of final formulation.

The potted plants (one pot per compound tested) infested with 100-150aphids, were placed on a revolving turntable and sprayed with 100-110milliliters of test compound formulation by use of a DeVilbiss spray gunset at 40 psig. air pressure. This application, which lasted 25 seconds,was sufficient to wet the plants to run-off. As a control, 100-110milliliters of a water-acetone-emulsifier solution containing no testcompound were also sprayed on infested plants. After spraying, the potswere placed on their sides on a sheet of white standard mimeograph paperwhich had been previously ruled to facilitate counting. Temperature andhumidity in the test room during the 24 hour holding period were 65°-70°F. and 50-70 percent, respectively. Aphids which fell onto the paper andwere unable to remain standing after being uprighted were considereddead. Aphids remaining on the plants were observed closely for movementand those which were unable to move the length of the body uponstimulation by prodding were considered dead. Percent mortality wasrecorded for various concentration levels.

Southern Armyworm Leaf Spray Test

Larvae of the southern armyworm (Prodenia eridania, (Cram.)), reared onTendergreen bean plants at a temperature of 80±5° F. and a relativehumidity of 50±5 percent, constituted the test insects.

The test compounds were formulated by diluting the stock suspension withwater to give a suspension containing 500 parts of test compound permillion parts of final formulation. Potted Tendergreen bean plants ofstandard height and age were placed on a revolving turntable and sprayedwith 100-110 milliliters of test compound formulation by use of aDeVilbiss spray gun set at 10 psig air pressure. This application, whichlasted 25 seconds, was sufficient to wet plants to run-off. As acontrol, 100-110 milliliters of a water-acetone-emulsifier solutioncontaining no test compound were also sprayed on infested plants. Whendry, the paired leaves were separated and each one was placed in a 9centimeter Petri dish lined with moistened filter paper. Five randomlyselected larvae were introduced into each dish and the dishes wereclosed. The closed dishes were labeled and held at 80°-85° F. for 3days. Although the larvae could easily consume the whole leaf withintwenty-four hours, no more food was added. Larvae which were unable tomove the length of the body, even upon stimulation by prodding, wereconsidered dead. Percent mortality was recorded for variousconcentration levels.

Mexican Bean Beetle Leaf Spray Test

Fourth instar larvae of the Mexican bean beetle (Epilachna varivestis,Muls.), reared on Tendergreen bean plants at a temperature of 80±5° F.and 50±5 percent relative humidity, were the test insects.

The test compounds were formulated by diluting the stock suspension withwater to give a suspension containing 500 parts of test compound permillion parts of final formulation. Potted Tendergreen bean plants ofstandard height and age were placed on a revolving turntable and sprayedwith 100-110 milliliters of test compound formulation by use of aDeVilbiss spray gun set at 10 psig air pressure. This application, whichlasted 25 seconds, was sufficient to wet plants to run-off. As acontrol, 100-110 milliliters of a water-acetone-emulsifier solutioncontaining no test compound were also sprayed on infested plants. Whendry, the paired leaves were separated and each was placed in a 9centimeter Petri dish lined with moistened filter paper. Five randomlyselected larvae were introduced into each dish, and the dishes wereclosed. The closed dishes were labeled and held at a temperature of80±5° F. for 3 days. Although the larvae could easily consume the leafwithin 24 to 48 hours, no more food was added. Larvae which were unableto move the length of the body, even upon stimulation, were considereddead.

Fly Bait Test

Four to six day old adult house flies (Musca domestica, L.), rearedaccording to the specifications of the Chemical SpecialitiesManufacturing Association (Blue Book, McNair-Dorland Co., N.Y. 1954;pages 243-244, 261) under controlled conditions of 80±5° F. and 50±5percent relative humidity, were the test insects. The flies wereimmobilized by anesthetizing with carbon dioxide and twenty fiveimmobilized individuals, males and females, were transferred to a cageconsisting of a standard food strainer about five inches in diameterwhich was inverted over a wrapping-paper-covered surface. The testcompounds were formulated by diluting the stock suspension with a 10percent (by weight) sugar solution to give a suspension containing 500parts of test compound per million parts of final formulation, byweight. Ten milliliters of the test formulation were added to a soufflecup containing a one-inch square of an absorbent cotton pad. This baitcup was introduced and centered on the blotting paper under the foodstrainer prior to admitting the anesthetized flies. The caged flies wereallowed to feed on the bait for 24 hours, at a temperature of 80±5° F.and the relative humidity of 50±5 percent. Flies which showed no sign ofmovement on prodding were considered dead.

Mite Foliage Spray Test

Adults and numphal stages of the two-spotted mite (Tetranychus urticaeKoch), reared on Tendergreen bean plants at 80±5 percent relativehumidity, were the test organisms. Infested leaves from a stock culturewere placed on the primary leaves of two bean plants six to eight inchesin height, growing in a two-and-a-half inch clay pot. 150-200 Mites, asufficient number for testing, transferred from the excised leaves tothe fresh plants in a period of twenty four hours. Following the twentyfour hour transfer period, the excised leaves were removed from theinfested plants. The test compounds were formulated by diluting thestock suspension with water to give a suspension containing 500 parts oftest compound per million parts of final formulation. The potted plants(one pot per compound) were placed on a revolving turntable and sprayedwith 100-110 milliliters of test compound formulation by use of aDeVilbiss spray gun set at 40 psig. air pressure. This application,which lasted 25 seconds, was sufficient to wet the plants to run-off. Asa control, 100-110 milliliters of a water solution containing acetoneand emulsifier in the same concentrations as the test compoundformulation, but containing no test compound, were also sprayed oninfested plants. The sprayed plants were held at 80±5 percent relativehumidity for 6 days, after which a mortality count of motile forms wasmade. Microscopic examination for motile forms was made on the leaves ofthe test plants. Any individual which was capable of locomotion uponprodding was considered living.

MITE SYSTEMIC TEST

Systemic treatments were made by drenching 20 milliliters of the testcompound formulation into the soil around the roots of bean plantsgrowing in 21/2 inch clay pots. These pots were held in 4 ounce waxpaper containers to prevent cross-contamination and loss by leaching.The plants were 4 inches high at the time of treatment and had beeninfested with mites 24 hours previously. Subsequent steps for testing ofthe systemic miticidal activity were the same as those described abovefor the spray method of application.

NEMATOCIDE TEST

The test organism used was the infective migratory larvae of theroot-knot nematode, Meloidogyne incognita var. acrita, reared in thegreenhouse on roots of cucumber plants. Infected plants were removedfrom the culture, and the roots are chopped very finely. A small amountof this inoculum was added to a pint jar containing approximately 180cc. of soil. The jars were capped and incubated for one week at roomtemperature. During this period eggs of the nematode were hatched, andthe larval forms migrated into the soil.

Ten ml. of the test formulation were added to each of the two jars foreach dosage tested. Following the addition of chemical, the jars werecapped, and the contents thoroughly mixed on a ball mill for 5 minutes.

The test compounds were formulated by a standard procedure of solutionin acetone addition of an emulsifier, and dilution with water. Primaryscreening tests were conducted at 3.33 m.g. of the test compound perjar.

The jars were left capped at room temperature for a period of 48 hours,and the contents then transferred to 3 inch pots. Subsequently, the potswere seeded to cucumber as an indicator crop and placed in thegreenhouse where they were cared for in the normal fashion forapproximately 3 weeks.

The cucumber plants were then taken from the pots, the soil removed fromthe roots, and the amount of galling visually rated.

In the tests described above, the pesticidal activity of the compoundsagainst aphid, mite, Southern Armyworm, Bean Beetle, house fly andnematode was rated as follows:

A = excellent control

B = partial control

C = no control

Certain of these compositions were also evaluated to determine theirperoral toxicity to mammals. The animal selected for this experiment wasthe rat. The test results obtained are expressed in terms of the numberof milligrams of composition per kilogram of weight of the animalrequired to achieve a mortality rate of 50 percent (LD₅₀).

The results of these tests are set forth in Table I below: Dashesindicate no test conducted.

                                      TABLE I                                     __________________________________________________________________________                              Mite Mite  Army-                                    Structure      m p c ° C                                                                     Aphid                                                                             (Spray)                                                                            (Systemic)                                                                          worm                                                                              Beetle                                                                            Fly                                                                              Nematode                                                                           Rat                      __________________________________________________________________________     ##STR3##      111-113                                                                              A   A    A     A   A   A  C    --                        ##STR4##      74-76  A   A    A     B   A   A  C    --                        ##STR5##      59-61  A   A    --    A   A   A  A    --                        ##STR6##      136-138                                                                              A   A    --    A   A   A  C    85.7                     __________________________________________________________________________

At higher dosage rates all of the above compositions may be expected toexhibit some activity against the various test species, however the datapresented in Table I above clearly indicates a rather high degree ofselectivity for some compositions and a broad spectrum of activity forothers.

It will be understood that the insect species employed in the abovetests are merely representative of a wide variety of pests that can becontrolled by use of my compounds. These compounds demonstrate systemicas well as contact toxicity against insects and mites.

It should be noted that in addition to their insecticidal and miticidalactivity, noteworthy nematocidal activity was also displayed by ourcompounds.

Comparison tests were conducted to assess the biological and chemicalproperties of certain representative species of the claimed invention inrelation to their corresponding N-methyl carbamate compositions. Thetest procedures described above were employed in these experiments inorder to determine the LD₅₀ (number of parts per million of activeingredients required to achieve fifty percent mortality of the insectstested) for each of the compositions tested. In the case of the aphidand mite tests a side by side comparison was made of the N-methylcarbamate composition versus the corresponding perhalomethylsulfenylderivative. The results of these experiments are set forth in Table IIbelow.

                                      TABLE II                                    __________________________________________________________________________    COMPARATIVE BIOLOGICAL ACTIVITY OF CERTAIN UNSUB-                             N-METHYLCARBAMATE COMPOSITIONS -STITUTED N-METHYLCARBAMATE THEIR COR-         RESPONDING SULFENYLATED DERIVATIVES (LD.sub.50 IN PPM                          ##STR7##                                                                                       Mites                                                                             Army-                                                   R    X  Stability                                                                           Aphids                                                                            Spray                                                                             worm                                                                              Beetle                                                                            Housefly                                                                           Rat                                        __________________________________________________________________________    H    CN (unstable)                                                                          12  40   55 65  3    9.5                                        SCCl.sub.3                                                                         CN (stable)                                                                            23  23   50 45  7    28.3                                       SCF.sub.3                                                                          CN (stable)                                                                            38  90  300 40  14   --                                          ##STR8##                                                                     H    -- (stable)                                                                             8   8  5   25  2    7.7                                        SCCl.sub.3                                                                         -- (stable)                                                                            10  22  6   15  3    85.7                                       __________________________________________________________________________

These experimental results clearly demonstrate the remarkable reductionin mammalian toxicity achieved with the present compositions incomparison to their corresponding N-methylcarbamate derivatives as wellas their improved chemical stability.

The compounds contemplated in this invention may be applied asinsecticides, miticides and nematocides according to methods known tothose skilled in the art. Pesticidal compositions containing thecompounds as the active toxicant will usually comprise a carrier and/ordiluent, either liquid or solid.

Suitable liquid diluents or carriers include water, petroleumdistillates, or other liquid carriers with or without surface activeagents. Liquid concentrates may be prepared by dissolving one of thesecompounds with a nonphytotoxic solvent such as acetone, xylene, ornitrobenzene and dispersing the toxicants in water with the aid ofsuitable surface active emulsifying and dispersing agents.

The choice of dispersing and emulsifyng agents and the amount employedis dictated by the nature of the composition and the ability of theagent to facilitate the dispersion of the toxicant. Generally, it isdesirable to use as little of the agent as is possible, consistent withthe desired dispersion of the toxicant in the spray so that rain doesnot re-emulsify the toxicant after it is applied to the plant and washit off the plant. Nonionic, anionic, or cationic dispersing andemulsifying agents may be employed, for example, the condensationproducts of alkylene oxides with phenol and organic acids, alkyl arylsulfonates, complex ether alcohols, quaternary ammonium compounds, andthe like.

In the preparation of wettable powder or dust or granulatedcompositions, the active ingredient is dispersed in and on anappropriately divided solid carrier such as clay, talc, bentonite,diatomaceous earth, fullers earth, and the like. In the formulation ofthe wettable powders the aforementioned dispersing agents as well aslignosulfonates can be included.

The required amount of the toxicants contemplated herein may be appliedper acre treated in from 1 to 200 gallons or more of liquid carrierand/or diluent or in from about 5 to 500 pounds of inert solid carrierand/or diluent. The concentration in the liquid concentrate will usuallyvary from about 10 to 95 percent by weight and in the solid formulationsfrom about 0.5 to about 90 percent by weight. Satisfactory sprays,dusts, or granules for general use contain from about 1/4 to 15 poundsof active toxicant per acre.

The pesticides contemplated herein prevent attack by insects, mites andnematodes upon plants or other material to which the pesticides areapplied, and they have relatively high residual toxicity. With respectto plants, they have a high margin of safety in that when used insufficient amount to kill or repel the insects, they do not burn orinjure the plant, and they resist weathering which includes wash-offcaused by rain, decomposition by ultra-violet light, oxidation, orhydrolysis in the presence of moisture or, at least, such decomposition,oxidation, and hydrolysis as would materially decrease the desirablepesticidal characteristic of the toxicants or impart undesirablecharacteristics, for instance, phytotoxicity, to the toxicants. Thetoxicants are so chemically inert that they are now compatible withsubstantially any other constituents or the spray schedule, and they maybe used in the soil, upon the seeds, or the roots of plants withoutinjuring either the seeds or roots of plants. They may also be used incombination with other active ingredients such as miticides,insecticides and herbicides.

I claim:
 1. An insecticide, miticide or nematocide compositioncomprising an acceptable carrier and an insecticidally, miticidally ornematocidally effective amount of a compound of the formula: ##STR9##wherein R is:A. lower alkyl; B. lower alkyl substituted with one or morelower alkoxy, lower alkylthio, lower alkylsulfinyl, lower alkylsulfonyl,phenylthio, phenylsulfinyl, phenylsulfonyl or R₄ CON(R₅)-, all of whichmay be substituted with one or more cyano, nitro, azido, chloro, bromoor fluoro substituents; R₁ is:A. hydrogen, chlorine, bromine, fluorine,cyano; B. alkyl having from 1 to 4 carbon atoms, lower alkylthio, loweralkoxy, lower carboalkoxyalkylthio, lower alkylthioalkyl, all of whichmay either be unsubstituted or substituted with one or more chloro,bromo, fluoro cyano or nitro groups; R₂ is: lower alkyl or lower alkylsubstituted with one or more chloro, bromo, fluoro, nitro, cyano, loweralkoxy or lower alkyl groups; R₃ is: perhalomethanesulfenyl orperhaloethanesulfenyl wherein halogen substituents are chloro, bromo orfluoro; R₄ and R₅ are individually hydrogen or lower alkyl; with theproviso that:A. when R is alkyl, R₁ is substituted lower alkyl,substituted lower alkylthio, unsubstituted or substituted lower alkoxy,unsubstituted or substituted lower carboalkoxyalkylthio or unsubstitutedor substituted lower alkylthioalkyl; B. when R₁ is hydrogen, R is otherthan unsubstituted lower alkylthioalkyl; and C. at least one of thegroups R, R₁ and R₂ is a group including one or more cyano substituentswhen R₁ is other than cyano.
 2. The composition of claim 1 wherein thetotal number of aliphatic carbon atoms in the substituents R, R₁, R₂ andR₃ does not exceed about ten carbon atoms.
 3. The composition of claim 1wherein R₂ is lower alkyl and R₃ is perhalomethanesulfenyl.
 4. Thecomposition of claim 1 wherein the cumulative sigma* value of the groupsR and R₁ is at least 1.1.
 5. The composition of claim 1 wherein R₁ islower alkyl.
 6. The composition of claim 1 wherein R₁ is hydrogen. 7.The composition of claim 1 wherein R₁ is substituted lower alkylthio. 8.The composition of claim 1 wherein R is lower alkyl substituted with oneor more lower alkylthio groups.
 9. The composition of claim 1 wherein Ris a nitro substituted lower alkyl.
 10. The composition of claim 1wherein R is a cyano subsituted lower alkyl.
 11. The composition ofclaim 1 wherein R is lower alkylsulfinylalkyl.
 12. The composition ofclaim 1 wherein R is lower alkylsulfonyl.
 13. The composition of claim 1wherein said compound is 2-Methyl-2-cyanopropionaldehyde(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.
 14. The compositionof claim 1 wherein said compound is 1-(2-Cyanoethylthio)acetaldehydeO-(N-methyl-N-trichloromethanesulfenylcarbamoyl)oxime.
 15. A method ofcontrolling insects, mites and nematodes which comprises applying tosaid pests, an insecticidally, miticidally or nemato cidally effectiveamount of a compound of the formula: ##STR10## wherein R is:A. loweralkyl; B. lower alkyl substituted with one or more lower alkoxy, loweralkylthio, lower alkylsulfinyl, lower alkylsulfonyl, phenylthio,phenylsulfinyl, phenylsulfonyl or R₄ CON(R₅)--, all of which may besubstituted with one or more cyano, nitro, azido, chloro, bromo orfluoro substituents; R₁ is:A. hydrogen, chlorine, bromine, fluorine,cyano; B. alkyl having from 1 to 4 carbon atoms, lower alkylthio,alkoxy, carboalkoxyalkylthio, alkylthioalkyl, all of which may either beunsubstituted or substituted with one or more chloro, bromo, fluorocyano or nitro groups, R₂ is: lower alkyl or lower alkyl substitutedwith one or more chloro, bromo, fluoro, nitro, cyano, lower alkoxy orlower alkyl group; R₃ is: perhalomethanesulfenyl orperhaloethanesulfenyl wherein halogen substituents are chloro, bromo orfluoro; R₄ and R₅ are individually hydrogen or lower alkyl; with theproviso that:A. when R is alkyl, R₁ is substituted lower alkyl,substituted lower alkylthio, unsubstituted or substituted lower alkoxy,unsubstituted or substituted lower carboalkoxyalkylthio or unsubstitutedor substituted lower alkylthioalkyl; B. when R₁ is hydrogen, R is otherthan unsubstituted lower alkylthioalkyl; and C. at least one of thegroups R, R₁ and R₂ is a group including one or more cyano substituentswhen R₁ is other than cyano.